#32 Array of Objects in Java

Check out our courses:
Spring and Microservices Weekend Live Batch : bit.ly/spring-live-weekend
Coupon: TELUSKO10 (10% Discount)
Master Java Spring Development : bit.ly/java-spring-cloud
Udemy Courses:
Java:- bit.ly/JavaUdemyTelusko
Spring:- bit.ly/SpringUdemyTelusko
Java For Programmers:- bit.ly/javaProgrammers
For More Queries WhatsApp or Call on : [phone]
website : courses.telusko.com/
In this lecture we are discussing about array of objects:
-- If we create array by default value assign for each type of array
-- The new operator automatically initializes the elements of an array to their default value, which, for example, is zero for all numeric types
and null for all reference types.
-- why we should we know length of array using length property?
-- There is array out of bound exception.
How to create array of object and what does it means?
-- just like to create array for int, float, char we can create array of object
-- when we we create array of object it means we create an array which can hold the reference of object.
e.g
class Student{
}
Student st=new Student();
we know st is reference and new Student() is object.
and st hold reference of student object.
similarly whenever we create array of object
Student sts[]=new Student[5];
it means we can create an array of Student reference type which can hold 5 different reference of
Student object.
sts[0]=new Student();
sts[1]=new Student();
sts[2]=new Student();
sts[3]=new Student();
sts[4]=new Student();
Github repo : github.com/navinreddy20/Javac...
Java:- bit.ly/JavaUdemyTelusko
Spring:- bit.ly/SpringUdemyTelusko
More Learning :
Java :- bit.ly/3x6rr0N
Python :- bit.ly/3GRc7JX
Django :- bit.ly/3MmoJK6
JavaScript :- bit.ly/3tiAlHo
Node JS :- bit.ly/3GT4liq
Rest Api :-bit.ly/3MjhZwt
Servlet :- bit.ly/3Q7eA7k
Spring Framework :- bit.ly/3xi7buh
Design Patterns in Java :- bit.ly/3MocXiq
Docker :- bit.ly/3xjWzLA
Blockchain Tutorial :- bit.ly/3NSbOkc
Corda Tutorial:- bit.ly/3thbUKa
Hyperledger Fabric :- bit.ly/38RZCRB
NoSQL Tutorial :- bit.ly/3aJpRuc
Mysql Tutorial :- bit.ly/3thpr4L
Data Structures using Java :- bit.ly/3MuJa7S
Git Tutorial :- bit.ly/3NXyCPu
Donation:
PayPal Id : navinreddy20
www.telusko.com

[@elikmtl7730]

The best explanation of Array of Objects in Thank you!🙏

[@owl166]

Can we use collection framework to create an array of objects.....??
Thanks in advance

[@actandrepeat]

Is the length property a static attribute of the array object?

[@kazialhasan5433]

Getting error when Student class is not Static. But Navin didn't have it as static. What am I doing wrong?

[@user-px5pj7ux5k]

Nice sir, can you do this using with constructor?

[@tejaswinigm2606]

I have a list which I got from DB query based on few conditions, which contains below location details... I want o/p as segregated locations i.e all cities and zipcodes into its state, all states into country
Cou1 state1 city1 zip1
Cou1 state2 city2 zip2
Cou1 state1 city 3 zip3
O/p sld be as
Cou1
State1
Cit1 - zip1
Cit3 - zip3
State2
Cit2 - zip2

[@AbdulAhad-uj1nf]

First comment from #SriLanka.Thanks you so much for your help

[@jooyeonsimp]

So array is going to store objects values in place of objects ?? Basically in a array each element consists of 3 different student values

[@0shaad]

How without proper {} this code is working,
You open { in last class and in main method but didn't close it

[@pankajSingh-nh2qi]

public static void main(String[] args) use this if showing error

[@ankitbaranwal883]

What is the difference b/w array of objects and collection functionality wise

[@singirikumar2782]

Collection functionality wise ...
If u create a object as collections
U can access lot of methods to perform CRUD operations on data
Which is in collection..nd also growable in nature size wise nd it follows some data Structures...i.e data in some order ..ascending or descending but if u create object as array ...it is fixed u cannot add new data and u cannot delete and allows it won't follow data structures
When ever u r requirement is fixed heterogenous data and no need of delete of data .. we will go for Object array ..

[@niksyt8666]

i got an error

[@faltuCoder35]

seson 2 kha hai bhae

[@HariPrasad-qe3hd]

More precise way
for(Student s: students) {
System.out.println(s.name + ":" + s.mark);
}

[@simikhuzwayo]

3:40 Good explanation

[@puruagni1927]

Why are you not updating VS Code? Please update VS Code.

[@aninditadas7348]

Hello Sir,
Getting below error
error: cannot find symbol
Student s1=new Student();
^
symbol: class Student
location: class ArrayObject
ArrayObject.java:4: error: cannot find symbol
Student s1=new Student();
^
symbol: class Student
location: class ArrayObject
2 errors
MY code
class ArrayObject{
public static void main(String a[]){

Student s1=new Student();


}
}

[@aninditadas7348]

I got it solved, by creating a class using Student. Below is the code
class Student{
String name="";
int age= 0;
}

[@pierreoosthuizen9444]

What EDI do you use?

[@dhruvinbhatt6414]

I think it's VS CODE

[@informationtechtips5391]

Vs code

[@royalgaming3132]

VS Code (Visual studio code)

[@user-jm3ou8lo6v]

EDI or IDE 😂

[@Jake-cb8dm]

@@user-jm3ou8lo6vman I thought I was losing my mind thinking the community changed the name

[@RaviYash-fs2gh]

I have two doubts here, 1.When we create an object the class name should be same 2. When we create the three student objects you didnt intialize the data types for rollno, name, marks. If anyone knows please rectify my doubts. Thanks in advance

[@SPragnasya]

Okay let me address your doubts:
1. Yes, when you create an object in Java, the class name should be the same. For example:
Imagine you have a class called Student. If you want to make an actual student object, you say Student st = new Student();. This naming consistency helps others (and yourself) easily understand what type of object is being created.
class Student {
// Class definition
}
Student st = new Student(); // Creating an object of the Student class
2. Coming to your second doubt, consider the below example :
class Student {
int rollNo;
String name;
double marks;
}
public class Main {
public static void main(String[] args) {
Student st1 = new Student();
st1.rollNo = 1;
st1.name = "John";
st1.marks = 90.5;
Student st2 = new Student();
st2.rollNo = 2;
st2.name = "Jane";
st2.marks = 85.0;
}
}
In the Student class, you have defined three instance variables: int is the data type for rollNo, String for name, and double for marks. These are the data types for the respective fields.
In the Main class, you are creating two instances of the Student class (st1, st2) and initializing the data for each object.
Hope you understood 😊!

[@kvelez]

public class Main{
public static void main(String[] args) {
Student stud = new Student();
stud.roll = 1;
stud.marks = 88;
stud.name = "Kevin";
Student stud2 = new Student();
stud2.roll = 2;
stud2.marks = 78;
stud2.name = "Marco";
Student stud3 = new Student();
stud3.roll = 3;
stud3.marks = 90;
stud3.name = "Justin";
Student[] students = new Student[3];//Array with references
students[0] = stud;//Manual objects
students[1] = stud2;
students[2] = stud3;
for (Student student : students) {
System.out.print(student.name + " " + student.roll + " " + student.marks + "
");
}
}
}
class Student {
int roll;
int marks;
String name;
}

[@jitendratiwari4292]

In hindi?

[@sneha-yp2ew]

Is Kiran is your best friend???😁